Biomedical subjects

Li-Da Zhang

Publications and source records attributed to Li-Da Zhang.

2 recordsLinked to original sources

PubMed2003

[A new method for EST clustering].

We developed an EST (expressed sequence tag) clustering method, ESTClustering, to generate high-quality unique expressed sequence based on large-scale EST sequencing. The method uses consensus sequences to sequence analyze with megablast and assemble each cluster with phrap in clustering process. The clustering strategy can efficiently identify gene family and alternate splicing forms of expressed sequences. It can also reduce the adverse effects caused by sequence errors. The ESTClustering method tends to provide more expressed gene forms comparing with the UniGene clustering method of the National Center for Biotechnology Information. Analysis of the 112,256 ESTs of Arabidopsis with ESTClustering produced 23,581 EST clusters. Among these Arabidopsis EST clusters, 13,597 have corresponding genome coding sequences and this number is close to the number of genes predicted with Arabidopsis ESTs. Using this clustering method, a total of 147,191 rice ESTs were clustered into 33,896 groups.

Algorithms↗

PubMed2002

[Copia-like retrotransposon in Amaranthus].

This study analyzed the characteristics of reverse transcriptase sequences of copia-like retrotransposons in Amaranthus via PCR amplification and sequence approaches. The results are as follows: (1) The reverse transcriptase sequences of copia-like retrotransposons were detected in all 30 Amaranthus accessions studied, indicating that this class of retrotransposons is ubiquitous in Amaranthus; (2) Twenty-eight reverse transcriptases in A. quitensis were cloned and sequenced, showing extensive heterogeneity in base deletion mutation and stop codon mutation; (3) Cluster and alignment analyses of the 28 sequences and other published sequences of the reverse transcriptase from other species (such as rice, tomato and Drosophila) showed that the copia-like retrotransposons in A. quitensis have a close relationship with those in dicot and monocot plants. The evolution of copia-like retrotransposons in A. tricolor, which might be of the same origin as the copia and 1731 in Drosophila, was discussed.

Amaranthus↗